Setting up Hadoop using Ansible, we will be using cdh5 tarball for installation of the cluster.
This is a simple Hadoop playbook, to quickly start hadoop running in a cluster.
Here is the Script Location on Github
Below are the steps to get started.
Get the script from Github.
Below is the command to clone.
ahmed@ahmed-server ~]$ https://github.com/ahmedzbyr/ansible-playbooks-bigdata; cd ansible-playbooks-bigdata/hadoop_setup_targz
Before we start.
Download hadoop-2.3.0-cdh5.1.2.tar.gz
to file_archives
directory.
Download jdk-7u75-linux-x64.tar.gz
to file_archives
directory.
Details about each Playbook ‘Roles’.
Details about each Role.
commons
This role is used to update OS parameters and will update the below files.
sysctl.conf
Update swapiness, networking and more. Info indefaults/main.yml
limits.conf
Updatesoft
andhard
limits.90-nproc.conf
Update user based limits and addinghadoop_user
limits file./etc/hosts
Updatehosts
file on the server - fromhost_name
inhosts
file.
/etc/hosts
file will get the server information from the [allnodes]
group in the hosts
file.
NOTE : Commons will update the HOSTNAME
of the server as well as per these entries.
jdk
This role install jdk1.7. Installation path - from group_vars/all
with variable java_home
.
ssh_known_hosts
This role will create ssh known hosts for all the hosts in the hosts
file.
ssh_password_less
This role will make hadoop_user
passwordless user for hadoop
nodes.
cdh5_hadoop_commons_tarball
This role will install and configure hadoop installation. Update files.
core-site.xml
Add Namenode.hdfs-site.xml
Update hdfs parameters -default/main.yml
.mapred-site.xml
Update MR information.yarn-site.xml
Update Yarn.slaves
Update slaves information -hosts
file.hadoop-env.sh
UpdateJAVA_HOME
-group_vars
.
post_install_setups
This is hadoop user creation after installation.
If we need more users then we need to add them in role post_install_setups
.
Current we will create a user called stormadmin
. More details in roles/post_install_setups/tasks/create_hadoop_user.yml
#
# Creating a Storm User on Namenode/ This will eventually be a edge node.
#
- hosts: namenodes
remote_user: root
roles:
- post_install_setups
Step 1. Update below variables as per requirement.
Global Vars can be found in the location group_vars/all
.
# --------------------------------------
# USERs
# --------------------------------------
hadoop_user: hdadmin
hadoop_group: hdadmin
hadoop_password: <encrypted_password_here_howto_below>
# Common Location information.
common:
install_base_path: /usr/local
soft_link_base_path: /opt
Step 2. User information come from group_vars
.
Username can be changed in the Global Vars, hadoop_user
.
Currently the password is hdadmin@123
Password can be generated using the below python snippet.
# Password Generated using python command below.
python -c "from passlib.hash import sha512_crypt; \
import getpass; print sha512_crypt.encrypt(getpass.getpass())"
Here is the execution. After entering the password you will get the encrypted password which can be used in the user creation.
ahmed@ahmed-server ~]$ python -c "from passlib.hash \
import sha512_crypt; import getpass; print sha512_crypt.encrypt(getpass.getpass())"
Enter Password: *******
$6$rounds=40000$1qjG/2uPsmGK/2xnmOt80TjDwbof9rNvnYY6icCkdAR2qrFquirBtT1
ahmed@ahmed-server ~]$
Step 3. Update Host File.
IMPORTANT update contents of hosts
file.
In hosts
file host_name
is used to create the /etc/hosts
file.
#
# All pre-prod nodes.
#
[allnodes]
10.10.18.30 host_name=ahmd-namenode
10.10.18.31 host_name=ahmd-datanode-01
10.10.18.32 host_name=ahmd-datanode-02
10.10.18.34 host_name=ahmd-resourcemanager
10.10.18.93 host_name=ahmd-secondary-namenode
10.10.18.94 host_name=ahmd-datanode-03
10.10.18.95 host_name=ahmd-datanode-04
#
# hadoop cluster
#
[namenodes]
10.10.18.30
[secondarynamenode]
10.10.18.93
[resourcemanager]
10.10.18.34
[jobhistoryserver]
10.10.18.34
[datanodes]
10.10.18.31
10.10.18.32
10.10.18.94
10.10.18.95
[hadoopcluster:children]
namenodes
secondarynamenode
resourcemanager
jobhistoryserver
datanodes
#
# sshknown hosts list.
#
[sshknownhosts:children]
hadoopcluster
Step 4. Executing yml.
Execute below command.
ansible-playbook ansible_hadoop.yml -i hosts --ask-pass